From nobody Tue Feb 10 08:27:00 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 571A221345; Thu, 6 Mar 2025 02:18:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741227527; cv=none; b=TvHnJW4pPQuf0ny12nNpExjv38VYQVioIxhskuYkRmcQFKTiSa7n4v33nCr47wTIqZnBfWaHyDqjFxg+B2cb2e73qqe8HZFwhjG3TrTYgTcxl1A5EbwueYKn1fcxajcvY+f7NCAdhdubvSxsrubW3J4lSeEZQZHPlywKluC1RmA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741227527; c=relaxed/simple; bh=jLfpy/qnkcbGYZhTHsjTZaBDtnUpzhXTHsBHIvEg9Ek=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=X3H+hbdT4OCgHgvIwGS6Gq6FKXBLuEntc/YI0Th/4r+/Gjt8M1htdekz/mtycicQYVw0tzTlM+qCej/adwDlQa6cjSGz3bMjX2vInG2TOX+dLIJGqyD4sJTb8cn6+YG6RUqLYpszEnQZT1mj1q8VPwOHNq4GDHqXNjXluzqGnU8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8AxlnACBslnfsqLAA--.42334S3; Thu, 06 Mar 2025 10:18:42 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowMDxu8QABslnjKE4AA--.11561S3; Thu, 06 Mar 2025 10:18:41 +0800 (CST) From: Bibo Mao To: Tianrui Zhao , Huacai Chen Cc: WANG Xuerui , kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, Xianglai Li Subject: [PATCH v2 1/2] LoongArch: KVM: Reload guest CSR registers after S4 Date: Thu, 6 Mar 2025 10:18:39 +0800 Message-Id: <20250306021840.2120016-2-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20250306021840.2120016-1-maobibo@loongson.cn> References: <20250306021840.2120016-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowMDxu8QABslnjKE4AA--.11561S3 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Content-Type: text/plain; charset="utf-8" On host HW guest CSR registers are lost after suspend and resume operation. Since last_vcpu of boot CPU still records latest vCPU pointer so that guest CSR register skips to reload when boot CPU resumes and vCPU is scheduled. Here last_vcpu is cleared so that guest CSR registers will reload from scheduled vCPU context after suspend and resume. Signed-off-by: Bibo Mao --- arch/loongarch/kvm/main.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c index f6d3242b9234..af4d730196ef 100644 --- a/arch/loongarch/kvm/main.c +++ b/arch/loongarch/kvm/main.c @@ -317,6 +317,12 @@ int kvm_arch_enable_virtualization_cpu(void) kvm_debug("GCFG:%lx GSTAT:%lx GINTC:%lx GTLBC:%lx", read_csr_gcfg(), read_csr_gstat(), read_csr_gintc(), read_csr_gtlbc()); =20 + /* + * HW Guest CSR registers are lost after CPU suspend and resume. + * Clear last_vcpu so that Guest CSR registers forced to reload + * from vCPU SW state + */ + this_cpu_ptr(vmcs)->last_vcpu =3D NULL; return 0; } =20 --=20 2.39.3